John Hines writes:

In summary, as long as the same meter is used, the power company won't
know/care.

UNLESS...
a) the meter can't handle 100A and starts ablaze under heavy
load (unlikely, but possible I suppose)
or
b) the distribution transformer can't handle the number of
houses it currently serves if Joe Neighbor starts using
double his prior load capacity.


So, if the original poster starts noticing power sags about the same
time, say, their neighbor fires up their brand new [large current
device of some sort, enabled by the new service], then he'll be
suffering the problems associated with electricians quietly upgrading
services without the power company being notified.

Best Regards,
--
Todd H.
http://www.toddh.net/